Pipe threading machine



1932- M. ROSENKRANZ ET AL 1,884,260

PIPE THREADING MACHINE Filed Spt. 11. 1950 2 Sheets-Sheet 1 1 5 INVE T RS 071/51. 58 b AX Rosa/mm NZ. Wv flaw Oct. 25, 1932. M ROSENKRANZ ET AL 1,884,260

PIPE THREADING MACHINE Filed Sept. 11, 1930 2 Sheets-Sheet NKRA Z Armr'm E Y5.

Patented Oct. 25, 1932 PATENT OFFICE MAX ROSENKRANZ, OF LIBRARY, AND SAMUEL. WEBB; F; PITTSBURGH, PENNSYL- VANIA, ASSIGNORS TO NATIONAL TUBE COMPANY, Av CORPORATION OF. NEW

JERSEY PIPE THREADING MACHINE Application filed September 11, 1930. Serial No. 481,260.

This invention relates to pipe threading machines and it is among the objects thereof to provide mechanism for automatically I vide mechanism of the above designated char- 1 acter which shall provide for positive and accurate adjustment of the threading dies to maintain accuracy of the thread being cut;

Another object of the invention is the provision of die opening and closing mechanism in which the force acting upon the die holders to close the dies is utilized to hold the dies againsta stop to maintain the proper size of thread. I

These and other objects will become more apparent from a considerationof the accompanying drawings in which like'characters designate like parts and in'which:

Figure 1 is a side ele'vational view,fpartly in section, of the die operating mechanism, showing a portion of the pipe threading machine bed on which it is mounted.

Figure 2 is a top plan view of the structure shown in Figure 1. Figure 3 is a vertical cross-sectional view 30 through the dies and their cam operating mechanism.

Figure 4 is a front elevational view thereof. With reference to the several figures of the drawing, the structure therein illustrated comprises a machine bed 1 on which is mount ed a carriage generally designated at 2 which consists of a pair of die holders 3 pivotally mounted at 4, and constituting a pair of Winged members in whichthe thread cutting dies 5 are secured. The top of the die holders are provided with lugs 6 which cooperate with cam slots 7 of a camplate 8 shown in dotted lines in Figure 2, the cam being'adapted for sliding movement in a horizontal plane and being actuated by a piston rod 9 having a piston head 10 operatively disposed in an air cylinder 11.

The movement of the cam plate 8 is controlled by a valve 12 that is supported on the valve bracket 13 which is rigidly secured to the carriage 2. The valve body 12 is provided with ports 13, 14, 15, 16 and 17 which cooperate with a valve plunger 18 todirect air pressure to the operating cylinder 11 through ports 19 and 20.

The plunger 18 is provided withva head having a shoulder 21 for engagement'by a latch 22 that is mounted on a shaft 23, the latter being operated through a trigger 24 that is adapted to be actuated by a reamer plug 25 to release the latch 22. The reamer plug is slidably mountedin the carriage 2 and is held against rotation by a key 25a received in a ke The latch and trigger parts are held in their normal position by a spring 26 acting upon a'shaft 27 but are displaceable through the movement of the reamer 25. The latch 22 may be released by a hand lever 28 when it is desired to manually control the operation of the camplate.

The valve plunger 18 is provided with. a

bottom contact 30 which is adapted for en-, gagement with avalvellifter 31 that is piv-' otally mounted at 32 to a bracket 33 on the machine bed- 1 and the valve lifter. 31 is operated by the valve bracket 13 which has a contact or engagingportion 34 that liftsthe element 31 to raise the valve plunger 18 when the carriage 2 is returned to its normal position. The movement of the carriage 2 is con trolled throughsuitable operating linkage,

part of which is shown at 35 and'which functions to move the carriage back and forth on the bed 1 of the machine. An adjustable stop 36 is provided and is fastened to the end of the machine by a bracket 37 to determine the limit of movement'of the carriage 2.

One of the features of the invention is the provision of a combined stop and die adj usting device which comprises a wedge retainer 40 which is bolted to a die shoe 41, one ofthe bolts being shown at 41. A stop or wedge 42 is adapted to move backward and forward in the wedge retainer 40 and is adjusted therein by an adjusting nut 43 which can be locked in adjusted position by a lock nut 44.

The Wedge 42 is designed to engage the die holders when the dies are in their closed position, the wedge acting as a stop block against way 256 formed in the reamer. i

which the dies are forced. By means of the adjusting nut, the wedge 42 may be set to spread or contract the dies thereby providing for adjustment of the thread to be cut on the pipe.

The operation of the die closing and opening mechanism is briefly as follows: With the carriage 2 in position shown in Figure 1, resting against the stop 36, the valve lifter 31 is in engagement with the contact element 34 of. the valve bracket 13, and the plunger 18 is in its raised position with the latch 22 in engagement with the shoulder 21 of-the' plunger. In this position, fluid pressure is conducted through the port 13 around plunger 18 and out at the port which communicateswith the port 20 of the operating cylinder 11 at the'side where the fluid pressure will act upon the piston 10 to move it towards the back end of the carriage. Movement of the piston 10 will actuate the cam plate 8, causing it to move rearwardly and the cam slots, by virtue of their angularity, will contract the lugs 6 of the winged die holders, causing the die holders to close in engagement r with the wedge 42. The carriage is then ad vanced to engage the end of the pipe and the dies are fed automatically or by hand to form a thread on the pipe. When a thread of predetermined length has been cut, the reamer 25 manipulates the trig 'er 24 whereby the latch 22 is released and t 1e plunger 18 which is normally biased in a downward direction by a spring 1864, moves downwardly, thereby cutting'off the source of fluid pressure passing to cylinder 11 through the port 13 and causing the cylinder 11 to exhaust through the port 20, port 15 and the port 17. Simultaneously therewith, air pressure is directed from port 13 through port 14 to the back part of thecylinder 11 entering the latter through port 19 and causing the piston 10 to advance, thereby moving the cam plate in a direction to spread lugs 6 to open the die holders by virtue of the shape of the cam slots 7.

The carriage is then returned to rest against the stop 36 and as the contact portion of the valve bracket 13 engages the valve lifter 31, the plunger 18 is again restored to its uppermost position in which it is held by the latch 22. In this position air pressure is again communicated to the rear portion of the air cylinder 11 and the piston rod 9 is advanced to slide the cam plate 8 in a direction to contract or close the die holders until they abut against the wedge 42 which is the closed or cutting position of the dies.

The die holders may be operated by moving the hand lever 28 to release the latch 22 when desired.

By means of the die opening and closing mechanism herein described, the movement of the cam plate in a direction to hold the dies firmly against the wedge 42 and holder 47' produces greater accuracy of the dies in operation and by means of the adjusting of the wedge element 42, the dies may be spaced to produce very accurate threads.

Although one embodiment of tee invention has been herein illustrated and described, it will be obvious to those skilled in the art that various modifications may be made in the details of construction without departing from theprinciples herein set forth.

lVe claim:

1. A thread cutting mechanism comprising a movable carriage, a pair of die holders pivotally mounted thereon, a reaming plug car ried by said carriage and slidable relative thereto, said plug being adapted to be engaged by the pipe to ream the end thereof, a lug on each of said die holders, a horizontal cam plate having cam slots therein converging outwardly and rearwardly from said dieholders, said lugs on said die holders being mounted in said slots, a fluid pre sure actuatingmechanism for said cam plate comprising a piston, a valve controlling the pressure on both sides of said piston, a latch for holding said valve in position to close the dies, means operable by the movement of said carriage in a forward direction for moving said latch into holding position, said rean plug being adapted to be moved rearwardly relative to said carriage when thepipe being threaded engages said plug, and means adapted to be engaged and operated by said plug it moves rearwardly for releasing said latch to permit said valve to operate and open said dies.

2. A thread cutting mechanism comprising a movable carriage, a die shoe mounted on said carriage, a pair of die holders pivotally mounted on said die shoe, means for moving said die holders about their pivots to open and closed positions, a wedge retainer carried by said die shoe, a stop wedge mounted in said retainer and movable bacl: and forth between the free ends of said die holders to limit the movement of said die holders towards each other, a threaded stem on said wedge, a nut threaded on said stem and carried by said wedge retainer for adjusting sa d wedge, and means for locking said wedge in adjusted position.

In testimonywhereof, we have hereunto set our hands.

MAX RGSENKRANZ. SAMUEL WEBB. 

